Investigation of the functional contribution of neurons indigenous to the subthalamic region as well as lateral and medial hypothalamus to the regulation of food and water intake under ad libitum conditions and in response to various glucoprivic and hydrational challenges. Involves behavioral, endocrinological, and histological studies of the effects of electrolytic lesions, knife-cuts, and neurotoxin-produced lesions in the diencephalon. Attempts are made to relate the effects of brainlesions to peripheral metabolic disturbances by investigating the effects of peripheral nerve transection or pharmacological blockade of visceral afferents or efferents.